This is basically our WSO2 Identity Server product converted into a multi-tenant identity management system and hosted on Amazon EC2 for scalable and reliable deployment. Basically, within about 5 minutes you can register your domain, add your users and then have your own OpenID, Cardspace, SAML 2.0, WS-Trust STS for authentication and XACML and (very soon) OAuth for authorization. Translated to English, that means you can get a single place to manage your users and give them access to Drupal, Liferay, Google Apps and a whole lot more. We will soon be adding LDAP to this list as well, which means you can even tie Windows, Unix login to it as well as other services like SVN.

Nothing like giving it a try to see how it works!

[UPDATE] Here are some additional references for you to get started with: